But neither side is talking, so Secretary Powell is presenting the different viewpoints of the neighbors to each other. Careful not to use the word "mediate" - a word intolerable to India - Powell is "carrying some ideas" to New Delhi in an effort to start a bilateral dialogue on peace.

But weeks of phone calls and shuttle visits by Washington raise a larger question: Will the Indo-Pakistan standoff become a permanent nuclear flashpoint, a smaller-sized "Middle East" problem, that the US will feel a responsibility to broker in perpetuity?

"The US had always taken sort of a distant parental role toward us. You saw that in '99. But now they are in the trenches," says a Delhi official.

In the 48 hours after five gunmen stormed India's Parliament last month, outrage in Delhi was widespread here - a collective spasm of anger and shock.

Now US officials are worried about the possibility of bolder terrorist attacks in India - possibly by Pakistani extremists who want to upset a peace process, or exact revenge against General Musharraf's crackdown on Islamic radicals in Pakistan.

"All it takes is a major explosion, another bomb in Delhi, and you could see us again on the brink," says one Western official. "What worries me, after watching the speed of the reaction after Dec. 13 [the Parliament attack] is that India might not hesitate, as it did this time."

The nuclear threat - and the post-Sept. 11 war on terrorism in South and Central Asia - is forcing Washington to play a more active role.

"This government knows there can't be a war in South Asia," says Amitabh Mattoo, a member of India's National Security Advisory Council, downplaying recent fears. "India knows the US has new interests. But if there is the slightest element of doubt the US is not acting fairly, Delhi won't cooperate."

Diplomatically, South Asia is a cactus field of prickly sentiments. Pakistan may be eager for the US to enter the fray, hoping it will raise the issue of Kashmir. But India has long viewed any outside power-broker role with a mixture of obduracy and skepticism.

"Pakistan always wanted the US. India wants US influence, but selectively," says E. Sridharan, director of the University of Pennsylvania's Delhi office. "The problem is, once you are in a process, it doesn't work selectively. So we are going to see the US propose things the government of India may not like. Either way, the US is already involved."

Yesterday in Delhi, Powell indicated that the ball was now in India's court. In response to a question about India wanting see action - not words - from Musharraf, Powell ticked off the recent arrests of Islamic militants, and the banning of Pakistani groups conducting terrorism. "It's up to India to make a judgment," he said, as to whether this is enough to relax its stand.

On the Islamabad leg of his trip, Powell opened up the prickliest issue - Kashmir. He stated that for peace in the region, "the views of the Kashmiri people must be taken into account." But Powell did not call for a referendum in Kashmir - a vote sought by the 95 percent Muslim population on whether they wish to join India, Pakistan, or become independent. He said that the US "stands ready" to help in any talks over Kashmir.

Even raising the Kashmir issue shows the distance Washington has traveled since Sept. 11. For years, South Asia was scarcely on the US diplomatic radar. It re-appeared during a brief period of alarm in 1998 when India - followed by Pakistan - tested atomic devices, and in 1999 during the so-called "Kargil war" - an Indo-Pakistan conflict in the Himalayan mountains of Kashmir.

Today, Delhi wants Powell to pressure Pakistan to extradite 20 terrorists it has named in a list. Among them is the most hated Ibrahim Dawoo, who allegedly helped bomb the Bombay stock exchange in 1993.

Some Indians admit that, in the midst of major reforms to curb extremism in Pakistan, Musharraf is not in a position to do much more. Still, the "list of 20," is now a rallying cry in Delhi for some who are making it a litmus test of Musharraf's sincerity.

What Powell is unlikely to get, is what he most wants - a withdrawal of troops back from the border. What Powell is likely to push hard for are small confidence-building measures, such as the resumption of air, train, and bus routes between the two nations.